package com.sec.base.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class AesFileUtil {

	/**
	 * 对文件进行AES加密     
	 * 
	 * @param sourceFile     
	 * @param fileType       
	 * @param sKey           
	 * @return     
	 */
	public static File encryptFile(File sourceFile, File encrypfile, String sKey) {
		InputStream inputStream = null;
		OutputStream outputStream = null;
		try {
			inputStream = new FileInputStream(sourceFile);
			outputStream = new FileOutputStream(encrypfile);
			Cipher cipher = initAESCipher(sKey, Cipher.ENCRYPT_MODE);
			// 以加密流写入文件
			CipherInputStream cipherInputStream = new CipherInputStream(inputStream, cipher);
			byte[] cache = new byte[1024];
			int nRead = 0;
			while ((nRead = cipherInputStream.read(cache)) != -1) {
				outputStream.write(cache, 0, nRead);
				outputStream.flush();
			}
			cipherInputStream.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				inputStream.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
			try {
				outputStream.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return encrypfile;
	}

	/**
	 * AES方式解密文件     
	 * 
	 * @param sourceFile  要解密的文件路径     
	 * @param decryptFile 解密后的文件路径     
	 * @param sKey            
	 * @return     
	 */
	public static File decryptFile(File sourceFile, File decryptFile, String sKey) {
		InputStream inputStream = null;
		OutputStream outputStream = null;
		try {
			Cipher cipher = initAESCipher(sKey, Cipher.DECRYPT_MODE);
			inputStream = new FileInputStream(sourceFile);
			outputStream = new FileOutputStream(decryptFile);
			CipherOutputStream cipherOutputStream = new CipherOutputStream(outputStream, cipher);
			byte[] buffer = new byte[1024];
			int r;
			while ((r = inputStream.read(buffer)) >= 0) {
				cipherOutputStream.write(buffer, 0, r);
			}
			cipherOutputStream.close();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				inputStream.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
			try {
				outputStream.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return decryptFile;
	}

	/**
	 *  初始化 AES Cipher     
	 * 
	 * @param sKey           
	 * @param cipherMode      * @return     
	 */
	public static Cipher initAESCipher(String sKey, int cipherMode) {
		// 创建Key gen
		KeyGenerator keyGenerator = null;
		Cipher cipher = null;
		try {
			keyGenerator = KeyGenerator.getInstance("AES");
			keyGenerator.init(128, new SecureRandom(sKey.getBytes()));
			SecretKey secretKey = keyGenerator.generateKey();
			byte[] codeFormat = secretKey.getEncoded();
			SecretKeySpec key = new SecretKeySpec(codeFormat, "AES");
			cipher = Cipher.getInstance("AES");
			// 初始化
			cipher.init(cipherMode, key);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		}
		return cipher;
	}
}
